The specific aims of this project are to develop new techniques and new combinations of materials that will promote a viable interface layer which will also be antithrombogenic. Tissue culture studies by Braunwald have demonstrated the feasibility of growing in vivo, a viable layer of cells. The major drawback is that this layer is nonthrombogenic. From all indications it appears that the thrombotic characteristics are directly dependent upon the source of the multipotential cells that differentiate onto the morphology of the interface layer; i.e., connective tissue fibroblasts result in a thrombogenic surface and circulating cells in blood stream result in an antithrombogenic surface. The key to the problem appears to be the thickness of this developing interface layer. This investigation will primarily be aimed at promoting a thin, more physiologic layer on all types of surfaces. Our long-term goal is to construct artificial hearts and other vascular devices from these materials. Ideally no anticoagulants would ever have to be used.